{"id":"UBUNTU-CVE-2026-27601","details":"Underscore.js is a utility-belt library for JavaScript. Prior to 1.13.8, the _.flatten and _.isEqual functions use recursion without a depth limit. Under very specific conditions, detailed below, an attacker could exploit this in a Denial of Service (DoS) attack by triggering a stack overflow. Untrusted input must be used to create a recursive datastructure, for example using JSON.parse, with no enforced depth limit. The datastructure thus created must be passed to _.flatten or _.isEqual. In the case of _.flatten, the vulnerability can only be exploited if it is possible for a remote client to prepare a datastructure that consists of arrays at all levels AND if no finite depth limit is passed as the second argument to _.flatten. In the case of _.isEqual, the vulnerability can only be exploited if there exists a code path in which two distinct datastructures that were submitted by the same remote client are compared using _.isEqual. For example, if a client submits data that are stored in a database, and the same client can later submit another datastructure that is then compared to the data that were saved in the database previously, OR if a client submits a single request, but its data are parsed twice, creating two non-identical but equivalent datastructures that are then compared. Exceptions originating from the call to _.flatten or _.isEqual, as a result of a stack overflow, are not being caught. This vulnerability is fixed in 1.13.8.","modified":"2026-03-10T03:49:58.195794Z","published":"2026-03-03T23:15:00Z","upstream":["CVE-2026-27601"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-27601"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-27601"},{"type":"REPORT","url":"https://github.com/jashkenas/underscore/commit/411e222eb0ca5d570cc4f6315c02c05b830ed2b4"},{"type":"REPORT","url":"https://github.com/jashkenas/underscore/commit/a6e23ae9647461ec33ad9f92a2ecfc220eea0a84"},{"type":"REPORT","url":"https://github.com/jashkenas/underscore/security/advisories/GHSA-qpx9-hpmf-5gmw"}],"affected":[{"package":{"name":"ruby-rails-assets-underscore","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/ruby-rails-assets-underscore@1.8.3+dfsg-1?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.8.3+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.8.3+dfsg-1","binary_name":"ruby-rails-assets-underscore"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27601.json"}},{"package":{"name":"ruby-rails-assets-underscore","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/ruby-rails-assets-underscore@1.8.3+dfsg-1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.8.3+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.8.3+dfsg-1","binary_name":"ruby-rails-assets-underscore"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27601.json"}},{"package":{"name":"ruby-rails-assets-underscore","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/ruby-rails-assets-underscore@1.8.3+dfsg-4?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.8.3+dfsg-4"],"ecosystem_specific":{"binaries":[{"binary_version":"1.8.3+dfsg-4","binary_name":"ruby-rails-assets-underscore"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27601.json"}},{"package":{"name":"ruby-rails-assets-underscore","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/ruby-rails-assets-underscore@1.8.3+dfsg-5?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.8.3+dfsg-4","1.8.3+dfsg-5"],"ecosystem_specific":{"binaries":[{"binary_version":"1.8.3+dfsg-5","binary_name":"ruby-rails-assets-underscore"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27601.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}